Terminals may be divided into mobile/portable devices and stationary devices according to mobility. Also, the mobile terminals may be classified into handheld types and vehicle mount types according to whether or not a user can directly carry.
Functions of mobile terminals have been diversified. Examples of such functions include data and voice communications, capturing images and video via a camera, recording audio, playing music files via a speaker system, and displaying images and video on a display unit. Some mobile terminals include additional functionality which supports electronic game playing, while other terminals are configured as multimedia players. Specifically, in recent time, mobile terminals can receive broadcast and multicast signals to allow viewing of video or television programs
As it becomes multifunctional, a mobile terminal can be allowed to capture still images or moving images, play music or video files, play games, receive broadcast and the like, so as to be implemented as an integrated multimedia player.
Efforts are ongoing to support and increase the functionality of mobile terminals. Such efforts include software and hardware improvements, as well as changes and improvements in the structural components.
In recent years, there is an increasing need to provide communication services and multimedia services by mounting such mobile terminals in vehicles. Meanwhile, in relation to communication services, there is a need for a fifth-generation (5G) communication service, which is a next generation communication service, as well as existing communication services such as LTE (Long Term Evolution) and the like.
In this regard, discussion on the specification of the 5G communication service has not been completed, and an antenna system and a communication system for realizing such a service in a vehicle have not been discussed. In addition, a detailed method for implementing a flat antenna in relation to a method of loading a vehicle antenna system in the vehicle has not been presented.
In addition, the vehicle antenna system needs to support not only the 5G communication system but also a communication service such as LTE, which is an existing communication service. In this regard, the LTE supports a Multi-Input Multi-Output (MIMO) mode for improving transmission speed. However, in order to support the MIMO mode, isolation between LTE antennas is important. However, there is a problem that a method of ensuring sufficient isolation between the LTE antennas while maintaining sizes mountable in the vehicle has not been disclosed in detail.
On the other hand, the vehicle antenna system requires a capability of receiving satellite signals, and a patch antenna in which a silver paste is attached to a ceramic material is usually used as a satellite signal receiving antenna. However, this patch antenna has a problem that the ceramic substrate may be damaged by an external impact and an antenna performance may be deteriorated accordingly.